Lubricant containing metal compounds



gear lubricating compositions Patented May a, 1944 cosmonaucommons-rancomrolmn a 1 Stanley P. wuss. Westiield. n.1, to

Tidewater Associated N. J.-, acorporation ofDela Oil ware 'No Drawing.Applieation'llayzz, 1941, 1 Sa'ialNo.394,822",

I 'Q16Clainis. This invention "relates to improved mineral oilhibricattcompositions, and more particular- I! toimprovemenm known asextreme pressure lubricants.

For the past several automotive design has been toward engines ofincreased power. 1 This and other factors have resulted 'in operation ofautomobiles at higher and'more sustained speeds. In such operation thebearing surfaces oi gears such as transmission and diil'erential gearsof the modern automobile are subjected toextremely high unit pressuresin operation. This is particularly true in the case of diflerentialgears ofthe hypoid type now commonly used.

It is well known in theautomotive art that the ordinary niiheralbiilubricants formerly employed do not adequately lubricate such gearsunder these high pressure conditions, and this situation has given riseto the development of known in the art as extreme, pressure or E. P.lubricants.

The conventional E. P. lubricants comprise a suitable mineral oil and anadditional substance which imparts to the composition high loadcarryingcapacity. .Inmost types of E. P. iubrinature since the lubricatingeifectiveness of these compositions is apparently'due to the depositionupon thebea'ring surfaces of a high load-carrying film produced bychemicalreaction 'involv-Y ing the E.;P. agent. The-lubricat ng.eflectiveness of E. P. lubricants is thusnot due to'the viscosity andother characteristics of the mineral oil as in the case of the formerly.gear lubricants containing no E. P. 'agent', but is essentiallyattributable to theihigh load-carrying chemical nhn. V

Although some of the various extreme pressure lubricants heretoforeproposed have proved successful ior certain uses, a great many have notbeen satisfactory, particularly for the lubrication of hypoid gears inautomobiles and other automotive gears operating under particularly highpressure conditions, mainlybecaiise the additive agent fails to impartsufliciently highland-carryin: capacity to the compositions, and forother For example, it is known that the inin the type of compositionsthe tendency inor combined state, or certain a is that the E." Pjagenttherein be of chemically. reactive (oi. zsa-asi j a corporation or freesulfur in mineral oils increases the load-carrying capacity over that ofs cants. for hypoid gears and others under modern high-pressure p ratingconditions in respect to load-carrying capacity, and for the additionalreason that such compositions tend to cause-objectionable corrosion ofthe gear tooth surfaces.

10- Likewise; certain chlorine compounds and sulfur compounds providesome improvement in loadcarrying capacity but are insumcientlyeil'ective 'in this and other respects as E. P. ingredients for use inlubricants intended for the stated 1 services."

The present invention provides improved lubrigant compositions suitableand effective for the ilubrication of bearing surfaces operating underextremely highunit pressures. In'one 2 0.aspect the invention provides ameans for in creasing the E.' P; properties and other desirablecharacteristics of lubricant compositions of the type normallyconsidered efl'ective to some extent as extreme pressure lubricants forcertain 26 lubrication services.

I have found in accordance with this invention that "compounds ofantimony or bismuth are capable of "activating or promoting ex- 30 andthatby incorporating said metal compounds with said substances improvedE. P.

lubricant compositions result. By this means the load-carrying capacityof'free sulfur-containingjmin'eral oils, for example, vcanbe increasedfrom a point which as statedhereinabove isunsatisfactory iorlubricationof hypoid gears and the like to very satisfactory for tiveness in thisrespect of sulfur compounds, 40 chlorine compounds such, for instance,as those mentioned hereinabove, and others, can be likewise improved byincorporation of such metal compounds- Furthermore, the load-carryingcapacities of certain initia y i ective E. P. lubrlcantcompositions' canbe improved by incorporation of such'metal'compounds therein to thusprovide a higher safety factor or assured ieflectiveness to mcetfuturelubrication demands as respects higher unit pressures between bearing toanticipate future use in the automotive field of engines oi increasedpower.

As agents for use as "activators" or promoters of E. P. properties whenincorporatedaccording.

to this invention, I have found that both or- S me and inorganiccompounds of antimony and the 'mineral'oil alone, but many suchcompositions fall far short of being satisfactory lubri-' treme pressureprop rties of, many substances a load-carrying capacity this purpose.The eil'ec- 1 and the antimony trichloride.

' to about of the-total composition.

ethylates, have proved particularly suitable Likewise cyclic or aromaticderivatives are effective, examples of these being aromatic stibines orbismuthines, for example trlphenyl stibines and triphenyl bismuthines.Soaps of such metals are also satisfactory. Among the latter.- class maybe named soaps of cyclic nature such as naphthenates, for exampleantimonyhnaphthenates, or soaps of aliphatic straight chain acids.Antimony oleate may be mentioned as representative of the latter class.In general,- however, the metal soaps of the straight chain aliphaticacids are less effective than the other metal compounds discussedhereinabove.

The invention, broadly stated, comprises: lubricant compositionscontaining E. P. agents and having incorporated therein one or moremetal compounds of the class described hereinabove which is effective topromote or increase the load-carrying capacity of said agent.

The exact reason why theaddition of thedescribed metal compoundsimprovesthe load-carrying capacity of these compositions is notknown. Theimprovement cannot be attributed to an additive eifect, inasmuch as themetal compounds themselves have no appreciable E. P. properties. Inother words, the load-carrying capacity of a given lubricant compositionof this invention. containing say free sulfur and antimony trichlorldewill be very much greater than the sum of the respective load-carryincapacities of the sulfur 'Ihe lubricant compositions of the inventionthe composition occurs. For example, in the case of mineral oilcontaining sulfur in which. antimony has been incorporated, heating totemperatures of around 180 1''. or above may cause precipitation ofantimony sulfide, thus removing from solution important substances.Ordinarily temperatures up toabout 150-160 F. may be usedinthlsinstance.

The antimony or bismuth compounds are effec-' tive in .relatively smallamounts, generally in als, howevergit hasbeen found that in someinresults than is required of other metal compounds. Antimonysoapsforexample, should be added in minimum proportions of from aboutib fia Inorder to; evaluate the working accordance with the instant inventionsuch lubricants were tested on the S. A. E. lubricants tester.

. This machine is described in detail in B. A. B.

Journal, July 1936, page 293. It affords a recognised and standardizedtest for. determination of cants. Briefly, the machine comprises tworotab able hardened steel. test rin s rotated in opposite directionsagainst each: other so as to make theoretical line contact at-theirperipheries. The rings are rotated one clockwise at 890 R. P. H. and theother coimter-clockwise, the speed ratio being 14.8 to l, and a levermechanism is provided for increasing the force between the hearingsurfaces rate. The mechanical advantage of the lever is about 10 to 1and a scale is provided which indi-. cates in pounds (up to 600 pounds)the force applied to the lever. The oilto be tested is continuouslysupplied at the rubbing-rolling surface at which the rings form mutualcontact.

The pressure at which a given oil fails in this test is indicated by thescale reading-at the time when sparking occurs between the adjacent ringsurfaces. Sparking indicates that the ring surfaces have becomescored'or scufled and this may a be substantiated by subsequentinspection.

In the following tests on the S. A. E. tester the loading rate (scale)was 83.5 lbs/sec.

may be-prepared in any suitable manner. The metal'compound to be used-asthe promoter may be simply stirred into a suitable mineral oilconproportions of about 10% or less on the basis of the vwholecomposition and proportional amounts of about 1% have been foundsuitable .inmostca'ses. Inthecaseofsoapsofthesemet stances more isrequired to obtain satisfactory p a or load-carrying capacity oflubricants prepared in L actual load-carrying capacities, of E. P.-lubrl 1! Numerous lubricating compositions prepared in accordance withthe present invention were tested on this machine. In these tests thefollowing two blends of mineral oil were employed as the lubricant basefor the indicated assistant and promoter:

In these blends. the cylinder stock used was an unfiltered residual oilhaving a Baybolt viscosity at 210 F. of about 180 seconds, the brightstock a fllteredresidual stock derived from a Pennsylvania crude havinga Saybolt viscosity at 210' I". g

of approximately 150 and the pale oil a light-colored filtered oilhaving a Saybolt viscosity at I"; of approximately 200 seconds,

derived as anoverhead cut from a non-Pennsyl-v vanla crude. A thirdblend comprising heavy red oil, derived as distillate from a Columbiancrude. and pale oil was aswillappear.

Itis,ofcwrse,understoodthattheseblends were selected merely asconvenient oils for blendthelubricantwasflrstsubjectedtoamoresevere'heat test wherein said lubricant was heated at a temperature of 200l".,fos 84 hours prior to the S.A.B.telst.

'In' the following tests of examples of lubricating compositions of theinvention all withstood the maximum load of the 8. A. 3. machine asindicated by the fact that the maximum scale rea'dint wasreachcdwithoutfailure or reduction in effectivenessof the lubricants.

m {as m rcdnsd mm mu: m a m. se -s e 5% antimony iloamyhte 2. abovecomposition sullurised mineral oiloftheringsatadeflniteloadingalsousedillsomeofthetests an. wear "a; paleoil 44% pale es 1 added sulfur 1 .addedsullnr 1% cutaway isoamylatebimnth hoamylaie 33% pale oil I v The following test data from testsmade on the A S. A. E. tester under the same test conditions as 1% addedsulfur described hereinabove upon compositions similar 295mm? to thosedescribed but containing none of the %puleoil 1 i metal compounds ofthis invention afford com- 1 Wmtm parisongwhichbringout the efl'ectoftheaddi- 1% adde'd suliu rate tive activator or promoter agents: a in0.8% oloicacid I 21. mieflnedcylinda-stockpailedaggl-gopmmgss A E 56%steam refined qlinderstock 22. mom.zrbmrenederiao eundes.a.n.ieetereenemg: 134% nex oil Beet ten-101m. a w r. l! %chlori'm2edm} readins ur drumand dS.A.E.testescalc fiaflmdylsoamylate I 2s 92% ponn s r N. b(isS.A.E.teste {amnesiarennede nnde;sleek I \qmizifilmiind meltdo n r 31% ,itwt l Hm e The fact that the lubricant compositions of the 2%oleicsold v instant invention withstand the maximum load 2% on thee. in E.tester indicates them to have out- 56%steamreflnedcylinderstock standingload-carrying properties. Although it m%{ {44% pfle oi] 11 .1; t t-u b Qm L was impossible to determine exact load at "1110mm which thesecompositions would fail, due to the 2% antimony boamylate steam refinedcylinderstbck I corn oil (non-corrosive) 3% snty isosmylate steamrelined cylinder stock 44 ll Z i....... see... 27: 8b isoemyiate y {56%steam refined cylinderstock.

W. 957 449 c all 0s%{ {0.6 add d uliur 6% chlor ted war 2% antimonyisoarnyiate f. b naphthenate {56% steam refined cylinder stock 1% addedsuit 1% added sulfur 5% Sb naphthenate {56% steam refinedcylinder stock447 e .oll Heat test-l6 hrs. 9 ill" I.

i 1% 'eddd unu boleste {56% steam refined cylinder stock 447 011 Heattest-l6 is. a no r. m add d arl hrr o I 8% Base 11% triphenylstibine Wheavy red all limits of th testing machine, the condition of the testring surfaces after the'tests indicated that even considerably higherloads would not cause failure. The surfaces of the used test rings wereunusually smooth in contrast to suri'aces' of other rings which had beenused in testing certain other good E. P. lubricants. The rings showedsubstantially no signs of wear and no evidence of sending or I Anadditional advantageous feature of the'compositions of the-inventionresides in the fact that --the added metal compounds described alsofunction to inhibit corrosion of metal surfaces of parts beinglubricated by the composition. This is evidenced by the bright conditionof the S. A. E. machine .test rings used in testing these lubricants.These rings showed no evidence of pitting or undue chemical attack afteruse in the Thus, use of the lubricants of this invention in heavy dutygear lubrication will result in prolonged 'geer life in protecting. thebearing surfaces thereof irom undesirable chemical attack as well asfrom rapid physical wear. Certain substances herteoi'ore used as E. P.ingredients which normally are of such high chemical activity as tocause undesirable corrosion may be stabilized or inhibited in" thisrespect by incorporation of the described metal compounds.

The described metal compound are desirably employed in solution in themineral oil component, but need not be dissolved since they func--.

tion in suspension as well. the stated class which are soluble may ifdesired be r Metal compounds of substantially oil-indered soluble byfirst dissolving them in certain other substances. For

example, in preparing compositions numbered 18 and 19 hereinabove theantimony trichloride wasv first dissolved inpeanut oil and palm oilrespectively,. and these mixtures were added to the mineral oil blendsshown. Other solubillzing found effective, particularly pounds, arecertain phosphate esters such, for phosphate. In some of thecompositions, when allowed to stand for several hours, a slight sedl--mcnt mayi'orm. This, however, inno way detracts from the efl'ecflveneuexample, as lauryi as an E. P. lubricant.

Likewise, the mmbeeteuu e ui uee um eeide 8 11?! for antimony comwoodfatty acids and certain 1 of the composition flooholates oi the.described being particularly advantageous for the par-pom. oleic acid,for example.-f1mctlons in the sulfur compositions (see Formulae 5, 6 and'l) to stabilize the antimony alcoholates against hydrclization, thuspreventing precipitation of antimony sulfide which may normally occurunder high temperature conditions, such, for example, as is encounteredin the heat tests of Examples 6 and f. The presence of oleic acid doesnot reduce the loadcarrying capacities of the compositions, which issurprising in view of the fact that the normal effect of oleic acid inE. P. lubricants is to reduce load-carrying capacity. p

In addition to gear lubricants the invention is also applicable tovarious other types of lubricants. For example, cutting oils and thelike for use in extreme pressure metal working operations, and ingeneral all lubricants for use where high bearing pressures exist,areincluded within the scope" of the invention. I The invention alsoincludes methods of lubricating metal surfaces comprising applyingthereto the compositions disclosed herein.

I claim:

1. A lubricant composition comprising an E. P. agent and chlorinatedmaterials selected from the group consisting of sulfur, sulfurizedmaterials and a compound of a metal of the group consisting of antimonyand bismuth per se possessing no appreciable E. P. properties but beineffective to enhance the load-carrying capacity of said E. P. agent, themetal in said compound being in the monoatomicform.

2. A lubricant composition comprising mineral oil, an agent havingload-carrying capacity selected from the group consisting ofsulfursulfurized materials and chlorinated materials and a compound of ametal of the group consisting of antimony and bismuth per se possessingno appreciable load-carrying capacity but being effective to enhance theload-carrying capacity of said agent, the metal in said compound beingin the monoatomic form.

3. An extreme pressure lubricant composition I comprising mineral oiland a substance normally having low load-carrying capacity selected fromthe group consisting of sulfur, sulfurized materials and chlorinatedmaterials and a compound of the group consisting of antimony and bismuthsoap effective to increase the load-carrying capacity of the sulfur.

'l. A lubricant composition comprising an E. P. agent selected from thegroup consisting of sulfur, sulfuriaed materials and chlorinated mate-'rials and an alcoholate of a metal selected from the group'consistingof antimony and bismuth effective to enhance the load-carrying capacityof said E. P. agent.

8. A lubricantcomposition comprising a min-- eral lubricating oil.sulfur and an alcoholate of a metal selected from the group consistingof antimony and bismuth, said alcoholate being present in an amountsumcient to enhance the loadcarrying property of the sulfur.

9. A lubricant composition comprising a mineral lubricating oil, sulfurand a compound selected from the group consisting of antimony isoamylateand bismuth isoamylate, said compound being present in anamount-sufficient to enhance the load-carrying property of the sulfur,

10. A'lubricant composition comprising a mineral lubricating oil, asubstance having load-carrying capacity selected from the groupconsisting of sulfur, sulfurized materials and chlorinated materials,and a compound of a metal selected from the group consisting of antimonyand bis-' muth per se possessing no appreciable load-carrying capacitybut being effective to enhance the load-carrying properties of thesubstance of the first named group, the metal in said compound being inthe monoatomic form.

11. A lubricant composition comprising a mineral oil having dissolvedtherein sulfur and antiper se possessing no appreciable load-carrying Icapacity, but being effective to enhance the loadcarrying capacity ofsaid substance, the metal in said compound being in the monoatomic form.

4. A lubricant composition comprising a chicrinated material and acompound of a metal selected from the group consisting of antimony andbismuth effective to increase load-carrying capacity of saidchlorine-containing compound.

5. A lubricant composition comprising mineral oil, sulfur and a compoundof a metal of the .group consisting of antimony and bismuth per 'sepossessing no appreciable load-carrying capacity but being effective toincrease the load-carrying capacity of the sulfur, the metal in saidcompound being in the monoatomic form.

6. An extreme pressure lubricant composition comprising mineral oil,sulfur and anantimony effective to stabilize the solution, said antimonymony chloride, said antimony chloride being present in an amountsuifloient to enhance the loadcarrying property of the sulfur..

12. A lubricant composition comprising a mineral oil containing sulfur,having dissolved therein antimony chloride and an agent effective tostabilize the antimony chloride, said antimony chloride being present inan amount sufficient to enhance the load-carrying property of thesulfur.

13. A lubricant composition comprising a sulfur-containing mineral oilhaving dissolved therein antimony chloride and a vegetable ol effectiveto stabilize the solution, said antimony chloride being present in anamount sufficient to enhance the load-carrying property of the sulfur.

14. An extreme pressure lubricant composition comprising a mineral oilhaving dissolved therein sulfur, an antimony alcoholate and a fatty acidalcoholate being present in an amount sufiicient to enhance theload-carrying property of the sulfur.

15. An extreme pressure lubricant composition as described in claim 14,in which the fatty acid is oleic acid.

16. An extreme pressure lubricant composition comprising mineral oil,-a-load-carrying agent selected from the group consisting of sulfur,sulfurized materials and chlorinated materials, and a stibine effectiveto enhance the load-carrying properties of said agent.

' STANLEY P. WAUGH.

